Spi 21-069-0 Ruby Ball Contact Point Interapid Indicators

Product Description

The SPI 21-069-0 is a ruby ball contact point designed for use with Interapid test indicators. It provides a precise, wear-resistant contact surface for accurate measurement work on the shop floor or in the tool room. The ruby tip measures 0.078 inches in diameter and the total contact point length is 1.75 inches. Ruby is chosen for contact point tips because it resists wear and maintains dimensional consistency over repeated use, making it the preferred choice for precision measurement applications. Machinists, quality control technicians, and tool room professionals install and swap these contact points as part of routine indicator maintenance.

This contact point is intended for use with Interapid brand test indicators. It is well suited to surface runout checks, bore alignment, and fixture setup work where a small-diameter ball tip is needed to reach into tight geometries or contact curved surfaces. The 0.078 inch ball diameter allows contact on small radii and inside features where larger tips cannot reach reliably.

Key Features

• Ruby ball tip for superior wear resistance and long service life
• 0.078 inch ball diameter for contact on small radii and tight features
• 1.75 inch contact point length for reach in confined measurement setups
• Replacement contact point compatible with Interapid test indicators
• Lightweight at 0.1 pounds for minimal gauge loading

Compatibility

Designed for use with Interapid test indicators as stated by the manufacturer.

Installation Notes

Contact point replacement on test indicators is performed by precision measurement technicians or machinists familiar with indicator maintenance. Use the appropriate wrench or contact point tool to remove and install the tip without applying lateral force to the indicator spindle. Handle ruby tips carefully to avoid chipping the ball, which would compromise measurement accuracy. Zero the indicator and verify calibration after any contact point change.